Information processing apparatus, information processing method, program recording medium, and data recording medium

ABSTRACT

A management center registers user information that includes user identification information for identifying a user terminal and improvement-information identification information for identifying improvement information recorded in an optical disk and processed by the user terminal. When a user terminal requests improvement information through a network, the management center searches for another user terminal that can provide necessary information, according to user information, and obtains the improvement information from the another user terminal searched for, through the network. The management center then provides the obtained improvement information for the user terminal that requested it, through the network.

This is a continuation of co-pending application Ser. No. 11/502,003,filed Aug. 10, 2006, which is a continuation of application Ser. No.10/016,220, filed Oct. 30, 2001, now U.S. Pat. No. 7,130,476, grantedOct. 31, 2006, with a claim of priority under 35 USC 119 to JapaneseApplication 2000-332483, filed in Japan on Oct. 31, 2000, the entiretythereof being incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to information processing apparatuses,information processing methods, program recording media, and datarecording media, and more particularly, to an information processingapparatus, an information processing method, a program recording medium,and a data recording medium which allow the users to buy and sell to andfrom each other improvement information used for improving the qualityof purchased data.

2. Description of the Related Art

Conventionally, musical-piece data, for example, is recorded intorecording media, such as compact discs (CDs) and offered to the users.In these days, as the Internet has been widely used and acompression/decompression technology has progressed, contents such asmusical-piece data have been increasingly offered through networks.

In such an environment, it is expected that a new market will bedeveloped and a new business will be made if a system in which the userscan buy and sell purchased data to and from each other is provided. Morespecifically, in the system, for example, a user buys musical-piece databy a recording medium such as a CD or through a network, another useradds improvement information for improving the sound quality of themusical-piece data, and the users can buy and sell the improvementinformation to and from each other.

SUMMARY OF THE INVENTION

The present invention has been made in consideration of the abovesituation. Accordingly, it is an object of the present invention toallow the users to buy and sell to and from each other improvementinformation for improving the quality of purchased data.

The foregoing object is achieved in one aspect of the present inventionthrough the provision of an information processing apparatus includingreading means for reading data and improvement information used forimproving the quality of the data from a recording medium which storesthe data and the improvement information; improvement-informationrequesting means for requesting another improvement information used forimproving the quality of the data read by the reading means; and qualityimproving means for improving the quality of the data according to atleast the improvement information and the another improvementinformation obtained according to a request made by theimprovement-information requesting means and for outputting high-qualitydata.

The foregoing object is achieved in another aspect of the presentinvention through the provision of an information processing apparatusincluding reading means for reading data and improvement informationused for improving the quality of the data from a recording medium whichstores the data and the improvement information; improvement-informationrequesting means for requesting another improvement information used forimproving the quality of the data read by the reading means; qualityimproving means for improving the quality of the data according to atleast the improvement information and the another improvementinformation obtained according to a request made by theimprovement-information requesting means and for outputting high-qualitydata; and improvement-information sending means for sending theimprovement information to another information processing apparatus.

The foregoing object is achieved in still another aspect of the presentinvention through the provision of an information processing apparatusincluding storage means for storing user information which includes useridentification information used for identifying a user terminal, andimprovement-information identification information used for identifyingimprovement information improving the quality of data processed in theuser terminal; searching means for searching the storage means for theuser information having the improvement information requested by theuser terminal; improvement-information requesting means for requestingthe improvement information from another user terminal corresponding tothe user information searched for by the searching means; obtainingmeans for obtaining the improvement information from the another userterminal according to a request made by the improvement-informationrequesting means; and sending means for sending the improvementinformation obtained by the obtaining means to the user terminal.

The foregoing object is achieved in yet another aspect of the presentinvention through the provision of an information processing methodincluding the steps of reading data and improvement information used forimproving the quality of the data from a recording medium which storesthe data and the improvement information; requesting another improvementinformation used for improving the quality of the read data; andimproving the quality of the data according to at least the improvementinformation and the another improvement information obtained accordingto the request and outputting high-quality data.

The foregoing object is achieved in still yet another aspect of thepresent invention through the provision of an information processingmethod including the steps of reading data and improvement informationused for improving the quality of the data from a recording medium whichstores the data and the improvement information; requesting anotherimprovement information used for improving the quality of the read data;improving the quality of the data according to at least the improvementinformation and the another improvement information obtained accordingto the request and outputting high-quality data; and sending theimprovement information to another information processing apparatus.

The foregoing object is achieved in a further aspect of the presentinvention through the provision of an information processing methodincluding the steps of searching storage means for user informationhaving improvement information requested by a user terminal, the storagemeans storing user information which includes user identificationinformation used for identifying the user terminal andimprovement-information identification information used for identifyingimprovement information improving the quality of data processed in theuser terminal; requesting the improvement information from another userterminal corresponding to the user information searched for; obtainingthe improvement information from the another user terminal according tothe request; and sending the obtained improvement information to theuser terminal.

The foregoing object is achieved in a still further aspect of thepresent invention through the provision of a storage medium storing acomputer-controllable program, the program including the steps ofreading data and improvement information used for improving the qualityof the data from a recording medium which stores the data and theimprovement information; requesting another improvement information usedfor improving the quality of the read data; and improving the quality ofthe data according to at least the improvement information and theanother improvement information obtained according to the request andoutputting high-quality data.

The foregoing object is achieved in a yet further aspect of the presentinvention through the provision of a storage medium storing acomputer-controllable program, the program including the steps ofreading data and improvement information used for improving the qualityof the data from a recording medium which stores the data and theimprovement information; requesting another improvement information usedfor improving the quality of the read data; improving the quality of thedata according to at least the improvement information and the anotherimprovement information obtained according to the request and outputtinghigh-quality data; and sending the improvement information to anotherinformation processing apparatus.

The foregoing object is achieved in a still yet further aspect of thepresent invention through the provision of a storage medium storing acomputer-controllable program, the program including the steps ofsearching storage means for user information having improvementinformation requested by a user terminal, the storage means storing userinformation which includes user identification information used foridentifying the user terminal and improvement-information identificationinformation used for identifying improvement information improving thequality of data processed in the user terminal; requesting theimprovement information from another user terminal corresponding to theuser information searched for; obtaining the improvement informationfrom the another user terminal according to the request; and sending theobtained improvement information to the user terminal.

The foregoing object is achieved in an additional aspect of the presentinvention through the provision of a storage medium storing data; andimprovement information for improving the quality of the data and forimproving the quality of another data stored in another storage medium.

According to the present invention, data and improvement information forimproving the quality of the data are read, another improvementinformation for improving the quality of data is obtained, and thequality of the data is improved according to the improvement informationand the another improvement information. Therefore, improvementinformation is allowed to be bought and sold.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing an example structure of a network systemaccording to an embodiment of the present invention.

FIG. 2 is a view showing the format of data provided by a contentsprovider 1.

FIG. 3 is a view showing an ISRC format.

FIG. 4 is a view showing example improvement information.

FIG. 5 is a view showing the original data of a musical piece.

FIG. 6 is a view showing data obtained by sub-sampling the original dataof the musical piece.

FIG. 7 is a view showing data obtained by sub-sampling the original dataof the musical piece.

FIG. 8 is a view showing data obtained by sub-sampling the original dataof the musical piece.

FIG. 9 is a view showing data obtained by sub-sampling the original dataof the musical piece.

FIG. 10 is a flowchart of a manufacturing process of an optical disk 10.

FIG. 11 is a view showing improvement-information transfer between userterminals 2 through a management center 4.

FIG. 12 is a block diagram showing an example structure of a userterminal 2.

FIG. 13 is a flowchart of registration request processing performed by auser terminal 2.

FIG. 14 is a flowchart of reproduction processing performed by a userterminal 2 for data on an optical disk 10.

FIG. 15 is a flowchart of improvement-information acquisition processingperformed by a user terminal 2.

FIG. 16 is a flowchart of improvement-information providing processingperformed by a user terminal 2.

FIG. 17 is a block diagram showing an example structure of a managementcenter 4.

FIG. 18 is a flowchart of user registration processing performed by themanagement center 4.

FIG. 19 is a flowchart of improvement-information relay processingperformed by the management center 4.

FIG. 20 is a block diagram showing an example structure of a computeraccording to an embodiment of the present invention.

DETAILED DESCRIPTION

FIG. 1 shows an example structure of a network system (system refers toan object logically formed of a plurality of apparatuses irrespective ofwhether the apparatuses are disposed within a cabinet) according to anembodiment of the present invention.

A contents provider 1 offers to the users at user terminals 2 ₁ to 2_(N) contents such as musical-piece data together with improvementinformation, described later. The contents provider 1 can transfer themusical-piece data and the improvement information through a network 3,such as the Internet, a CATV network, or a public network, or cantransfer them by a recording medium 10, such as a CD, in which they havebeen recorded. In the following description, it is assumed that themusical-piece data and the improvement information are recorded into therecording medium 10 and distributed.

Each of the user terminals 2 ₁ to 2 _(N) (hereinafter collectivelycalled a user terminal 2 if it is not necessary to identify each ofthem) reproduces (reads) the musical-piece data recorded into therecording medium 10 purchased from the contents provider 1. Therecording medium 10 in which musical-piece data offered by the contentsprovider 1 has been recorded records the improvement information of themusical-piece data and improvement information for improving the soundquality of musical-piece data recorded into other recording media. Theuser terminal 2 performs improvement processing for improving the soundquality of the reproduced (read) musical-piece data by using theimprovement information and outputs the musical-piece data.

The user terminal 2 obtains improvement information other than thatrecorded into the recording medium 10 which the user owns, through thenetwork 3 from a management center 4 according to a request of the user,and performs improvement processing by using the improvementinformation. In addition, the user terminal 2 sends the improvementinformation recorded into the recording medium 10 which the user owns,to another user terminal 2 through the management center 4 according toa request of the management center 4.

The management center 4 mediates between user 2 through the network 3for improvement information. The management center 4 also performsaccounting processing for the consideration of improvement informationtransferred between user terminals 2.

FIG. 2 shows the format of the data stream of musical-piece data offeredby the contents provider 1. FIG. 2 shows the format of the data streamof one content, namely, one piece of musical-piece data in the presentembodiment.

A data stream offered by the contents provider 1 is formed of a data sethaving contents identification information, contents,improvement-information-identification information, and improvementinformation.

The contents identification information, disposed at the top, is usedfor identifying the contents, disposed thereafter. When the contents aremusical-piece data, an international standard recording code (ISRC), forexample, can be used in the contents identification information.

FIG. 3 shows the format of the ISRC.

In the ISRC, data L1 and L2 each having six bits indicates a nationcode, data L3 to L5 each having six bits indicates an owner code, dataL6 and L7 each having four bits indicates the year recording isperformed, and data L8 to L12 each having four bits indicates a recordserial number.

Back to FIG. 2, following the contents identification information,musical-piece data serving as the contents identified by the contentsidentification information is disposed. The improvement-informationidentification information is disposed after the contents. Theimprovement-information identification information indicates the type ofthe improvement information disposed thereafter.

The contents provider 1 divides the improvement information forimproving the sound quality of the musical-piece data serving as thecontents, and places each of a plurality of improvement-informationpieces obtained as a result of division in a different data stream. Inother words, the contents provider 1 divides the improvement informationfor a predetermined musical-piece data, adds each of theimprovement-information pieces obtained as a result of division to thepredetermined musical-piece data to form a plurality of types of datastreams.

Therefore, to improve the sound quality of musical-piece data disposedin a certain type of data stream to the highest level, it is necessaryto obtain improvement information disposed in all types of data streamsgenerated for the musical-piece data.

All types of improvement-information pieces (disposed in all types ofdata streams) are required to improve the sound quality of musical-piecedata to the highest level. The improvement-information identificationinformation indicates the type of improvement information disposedthereafter.

The improvement information of which the type is indicated by theimprovement-information identification information is disposed after theimprovement-information identification information.

In the embodiment shown in FIG. 2, the improvement information isdisposed after the musical-piece data. The improvement information canbe disposed, for example, before the musical-piece data or at the middleof the musical-piece data. Alternatively, it can be divided and disposedat any positions in the musical-piece data in a dispersion manner. It isalso possible that the improvement information is embedded into themusical-piece data by using an electronic watermark technology or thelike.

The improvement information will be described below by referring to FIG.4 to FIG. 9.

It is assumed as shown in FIG. 4(A) that the original data ofmusical-piece data is formed of 16 bits. In the 16 bits, the n-th bitcounted from the most significant bit is indicated by B_(#n-1).

The original data having 16 bits is, for example, divided into sixhigh-order bits B0 to B5 and 10 low-order bits B6 to B15. The 10low-order bits B6 to B15 are further divided, for example, into fivesets of two bits, B6 and B7, B8 and B9, B10 and B11, B12 and B13, andB14 and B15. These five sets of two bits serve as five types ofimprovement information. As shown in FIG. 4(B) to FIG. 4(F), the sixhigh-order bits serve as musical-piece data serving as a content, andthe five types of improvement information are added to the musical-piecedata to form five types of data streams for the musical-piece data.

When improvement-information pieces are sequentially obtained in theorder of B6 and B7, B8 and B9, B10 and B11, B12 and B13, and B14 andB15, the larger the number of obtained improvement-information piecesis, the more the sound quality of the musical-piece data is improved.

In the embodiment shown in FIG. 4, it is possible that two-bitimprovement information is attached as two low-order bits to six-bitmusical-piece data serving as a content and eight-bit musical-piece datais handled in the user terminal 2. In this case, however, inmusical-piece data having two low-order bits other than B6 and B7improvement information, those two low-order bits (improvementinformation) are handled as noise.

In the above case, the 10 low-order bits are simply divided into fivesets of two bits to make five types of improvement-information pieces.It is also possible that the 10 low-order bits are divided into fivesets of 10 bits which are added to obtain the original value and thefive sets serve as five types of improvement-information pieces. Also inthis case, it is possible that 10-bit improvement information isattached as 10 low-order bits to six-bit musical-piece data serving as acontent and 16-bit musical-piece data is handled in the user terminal 2.

In the embodiment shown in FIG. 4, improvement information for improvingmusical-piece data in terms of resolution (tone) in level has beendescribed. Improvement information for improving musical-piece data interms of resolution in a time domain can be employed.

When it is assumed, for example, as shown in FIG. 5 that the originaldata of musical-piece data is sampled at an interval of time Ts, it ispossible that the original data is sub-sampled at an interval of time4Ts with a phase being changed, as shown in FIG. 6 to FIG. 9, and fourobtained sub-sampling results are employed as four types ofmusical-piece data and improvement information disposed in data streams.In this case, the larger the number of obtained improvement-informationpieces is, the better the sound quality becomes. When the four types ofimprovement information are all obtained, the best sound quality isimplemented.

Since the musical-piece data and the improvement information are notdivided in the embodiment shown in FIG. 5 to FIG. 9, eithermusical-piece data (content) or improvement information can be omittedin the data format shown in FIG. 2.

As described above, if sampling results are just provided asmusical-piece data, an inconvenience such as aliasing occurs. To preventsuch an inconvenience, it is generally preferred that sampling resultsbe filtered by a low pass filter (LPF). When four sub-sampling resultsare filtered, it is difficult to restore the original data just bycollecting the four sub-sampling results. Therefore, in this case, it ispreferred that data close to the original data be obtained, for example,by the following class-classification adaptive processing in the userterminal 2 by using the four filtered sub-sampling results.

Class-classification adaptive processing is formed ofclass-classification processing and adaptive processing. Data isclassified into classes by its characteristics in theclass-classification processing, and the adaptive processing is appliedto each class. An incorporated reference of the class-classificationadaptive processing is U.S. Pat. No. 5,666,164.

In the adaptive processing, for example, musical-piece data (hereinaftercalled low-resolution data, if necessary) having a low time resolution(resolution in the time domain) is linearly coupled with predeterminedprediction coefficients to obtain the predicted value of high-resolutionmusical-piece data (hereinafter called high-resolution data, ifnecessary), which has been improved in time resolution, andmusical-piece data having a higher time resolution than thelow-resolution data is obtained.

More specifically, it is assumed that high-resolution data serves asmaster data, low-resolution data (sub-sampling results ofhigh-resolution data) obtained by reducing the time resolution of thehigh-resolution data serves as apprentice data, and the prediction valueE[y] of the high-resolution data “y” is obtained by a linear first-ordercoupling model defined by linear coupling of a set of somelow-resolution data x₁, x₂, . . . , and predetermined predictioncoefficients w₁, w₂, . . . . In this case, the prediction value E[y] canbe expressed by the following expression.

E[y]=w ₁ x ₁ +w ₂ x ₂+ . . .   (1)

To generalize the expression (1), when a matrix “W” formed of a set ofprediction coefficients “w_(j),” a matrix “X_(ij)” formed of a set ofapprentice data, and a matrix “Y′” formed of a set of prediction valuesE[y_(j)] are defined in the following expressions,

$X = \begin{bmatrix}x_{11} & x_{12} & \cdots & x_{1J} \\x_{21} & x_{22} & \cdots & x_{2J} \\\cdots & \cdots & \cdots & \cdots \\x_{I\; 1} & x_{I\; 2} & \cdots & x_{IJ}\end{bmatrix}$ ${W = \begin{bmatrix}W_{1} \\W_{2} \\\cdots \\W_{J}\end{bmatrix}},\; {{Y} = \begin{bmatrix}{E\lbrack y_{1} \rbrack} \\{E\lbrack y_{2} \rbrack} \\\cdots \\{E\lbrack y_{J} \rbrack}\end{bmatrix}}$

the following observation equation is satisfied.

XW=Y′  (2)

The element x_(ij) of the matrix X indicates the j-th apprentice data inthe i-th set of apprentice data (set of apprentice data used forpredicting the i-th master data y_(i)); the element w_(j) of the matrixW indicates a prediction coefficient to be multiplied by the j-thapprentice data in the set of apprentice data; y_(i) indicates the i-thmaster data, and therefore, E[y_(i)] indicates the prediction value ofthe i-th master data. In the left side of the expression (1), yrepresents the element y_(i) of the matrix Y with the suffix “i” beingomitted. In the right side of the expression (1), x₁, x₂, . . .represent the elements x_(ij) of the matrix X with the suffix “i” beingomitted.

The least squares method is applied to this observation equation toobtain a prediction value E[y] close to the high-resolution data “y.” Inthis case, when a matrix “Y” formed of a set of the true values “y” ofthe high-resolution data serving as master data, and a matrix “E” formedof a set of the remainders “e” of the prediction values E[y] against thetrue values “y” in the high-resolution data are defined in the followingway,

${E = \begin{bmatrix}e_{1} \\e_{2} \\\cdots \\e_{I}\end{bmatrix}},{Y = \begin{bmatrix}y_{1} \\y_{2} \\\cdots \\y_{I}\end{bmatrix}}$

the following remainder equation is satisfied from the expression (2).

XW=Y+E  (3)

In this case, prediction coefficients w_(j) used to obtain a predictionvalue E[y] close to the true value “y” of the high-resolution data areobtained when the following error square is made minimum.

$\sum\limits_{i = 1}^{I}\; e_{i}^{2}$

Therefore, when the result obtained by differentiating the above errorsquare by the prediction coefficient w_(j) is zero, in other words, theprediction coefficient w_(j) which satisfies the following expression isthe most appropriate value for obtaining a prediction value E[y] closeto the true value “y” of the high-resolution data.

$\begin{matrix}{{{e_{1}\frac{\partial e_{1}}{\partial w_{j}}} + {e_{2}\frac{\partial e_{2}}{\partial w_{j}}} + \ldots + {e_{I}\frac{\partial e_{I}}{\partial w_{j}}}} = {0\mspace{11mu} ( {{i = 1},2,\ldots \mspace{11mu},j} )}} & (4)\end{matrix}$

When the expression (3) is differentiated by the prediction coefficientw_(j), the following expression is satisfied.

$\begin{matrix}{{\frac{\partial e_{i}}{\partial w_{1}} = x_{i\; 1}},{\frac{\partial e_{i}}{\partial w_{2}} = x_{i\; 2}},\ldots \mspace{11mu},{\frac{\partial e_{i}}{\partial w_{J}} = x_{i\; J}},( {{i = 1},2,\ldots \mspace{11mu},I} )} & (5)\end{matrix}$

From the expressions (4) and (5), the expression (6) is obtained.

$\begin{matrix}{{{\sum\limits_{i = 1}^{I}\; {e_{i}x_{i\; 1}}} = 0},{{\sum\limits_{i = 1}^{I}\; {e_{i}x_{i\; 2}}} = 0},\ldots \mspace{11mu},{{\sum\limits_{i = 1}^{I}\; {e_{i}x_{iJ}}} = 0}} & (6)\end{matrix}$

In addition, when the relationships among the apprentice data “x_(ij),”the prediction coefficients “w_(j),” the master data “y_(i),” and theremainders “e_(i)” in the remainder equation (3) are taken into account,the following normal equations are obtained from the expression (6).

$\begin{matrix}\{ \begin{matrix}{{{( {\sum\limits_{i = 1}^{I}\; {x_{i\; 1}x_{i\; 1}}} )w_{1}} + {( {\sum\limits_{i = 1}^{I}\; {x_{i\; 1}x_{i\; 2}}} )w_{2}} + \ldots + {( {\sum\limits_{i = 1}^{I}\; {x_{i\; 1}x_{i\; J}}} )w_{J}}} = ( {\sum\limits_{i = 1}^{I}\; {x_{i\; 1}y_{i}}} )} \\{{{( {\sum\limits_{i = 1}^{I}\; {x_{i\; 2}x_{i\; 1}}} )w_{1}} + {( {\sum\limits_{i = 1}^{I}\; {x_{i\; 2}x_{i\; 2}}} )w_{2}} + \ldots + {( {\sum\limits_{i = 1}^{I}\; {x_{i\; 2}x_{i\; J}}} )w_{J}}} = ( {\sum\limits_{i = 1}^{I}\; {x_{i\; 2}y_{i}}} )} \\\cdots \\{{{( {\sum\limits_{i = 1}^{I}\; {x_{i\; J}x_{i\; 1}}} )w_{1}} + {( {\sum\limits_{i = 1}^{I}\; {x_{i\; J}x_{i\; 2}}} )w_{2}} + \ldots + {( {\sum\limits_{i = 1}^{I}\; {x_{iJ}x_{i\; J}}} )w_{J}}} = ( {\sum\limits_{i = 1}^{I}\; {x_{i\; J}y_{i}}} )}\end{matrix}  & (7)\end{matrix}$

When a matrix (covariance matrix) A and a vector “v” are defined asfollows:

$A = \begin{pmatrix}{\sum\limits_{i = 1}^{I}\; {x_{i\; 1}x_{i\; 1}}} & {\sum\limits_{i = 1}^{I}\; {x_{i\; 1}x_{i\; 2}}} & \cdots & {\sum\limits_{i = 1}^{I}\; {x_{i\; 1}x_{i\; J}}} \\{\sum\limits_{i = 1}^{I}\; {x_{i\; 2}x_{i\; 1}}} & {\sum\limits_{i = 1}^{I}\; {x_{i\; 2}x_{i\; 2}}} & \cdots & {\sum\limits_{i = 1}^{I}\; {x_{i\; 2}x_{i\; J}}} \\\; & \; & \cdots & \; \\{\sum\limits_{i = 1}^{I}\; {x_{i\; J}x_{i\; 1}}} & {\sum\limits_{i = 1}^{I}\; {x_{iJ}x_{i\; 2}}} & \cdots & {\sum\limits_{i = 1}^{I}\; {x_{i\; J}x_{iJ}}}\end{pmatrix}$ $v = \begin{pmatrix}{\sum\limits_{i = 1}^{I}\; {x_{i\; 1}y_{i}}} \\{\sum\limits_{i = 1}^{I}\; {x_{i\; 2}y_{i}}} \\\vdots \\{\sum\limits_{i = 1}^{I}\; {x_{iJ}y_{i}}}\end{pmatrix}$

and the vector W is defined as shown in expression (1), the normalequations (7) can be expressed by the following expression.

AW=v  (8)

The same number of the normal equations (7) as that of the predictioncoefficients “w_(j)” to be obtained can be formulated with a certainnumber of sets of apprentice data x_(ij) and master data y_(i) beingprepared. Therefore, by solving the equation (8) for the vector W (it isrequired that the matrix A be nonsingular in the expression (8) to solvethe expression (8)), the most appropriate prediction coefficients“W_(j)” is obtained. It is possible to use, for example, a sweep offmethod (Gauss-Jordan deletion method) to solve the equation (8).

In the adaptive processing, the most appropriate prediction coefficientsw_(j) are obtained as described above, and then the predictioncoefficients w_(j) are used to obtain a prediction value E[y] close tothe true value “y” of the high-resolution data by the expression (1).

The adaptive processing differs, for example, from simple interpolationprocessing in that components not included in low-resolution data butincluded in high-resolution data are reproduced. More specifically, theadaptive processing seems to be the same as interpolation processingusing a so-called interpolation filter when only the expression (1) isconsidered, but since the prediction coefficients w_(j), whichcorrespond to the tap coefficients of the interpolation filter, areobtained by learning with the use of the master data “y,” componentsincluded in the high-resolution data are reproduced. From this point ofview, it can be said that the adaptive processing has a resolutioncreating effect.

The case has been described for the adaptive processing, in which timeresolution is improved. According to the adaptive processing, masterdata and apprentice data used for obtaining prediction coefficients canbe changed to improve, for example, resolution in a level direction.

As described above, the class-classification adaptive processing can beused for obtaining data close to the original data by using fourfiltered sub-sampling results. In addition, it can be used asimprovement processing for improving the quality of musical-piece data.

When the class-classification adaptive processing is employed asimprovement processing, prediction coefficients can be used asimprovement information, and, for example, a selection pattern oflow-resolution data with which the sum-of-products calculation isapplied to the prediction coefficients according to the expression (1)can also be used. In the class classification of theclass-classification adaptive processing, several sets of low-resolutiondata are selected, and the low-resolution data is classified accordingto the distribution pattern in level of the several sets oflow-resolution data. The selection pattern of low-resolution data usedfor the class classification can also be used as improvementinformation. In the class classification, the low-resolution data isclassified according to the levels of the low-resolution data itself orthe differences between the levels. A method employed in the classclassification or a class-classification result can further be used asimprovement information.

In the present embodiment, musical-piece data, which is audio data,serves as contents of which the quality is to be improved. Image dataand others can also be employed as contents of which the quality is tobe improved. When image data serves as the contents, it is possible touse, for example, motion vectors or discrete cosine transform (DCT)coefficients as improvement information for improving the quality of theimage data. More specifically, when motion compensation or DCT isapplied to image data which serves as contents, low-order bits of motionvectors used for the motion compensation, or high-order DCT coefficientscan be used as improvement information.

The contents provider 1 provides the recording medium 10 in which a datastream having the format shown in FIG. 2 is recorded. It is assumed thatthe recording medium 10 is an optical disk, for example. Itsmanufacturing process will be described next by referring to a flowchartshown in FIG. 10.

In step S1, the contents provider 1 cleans a disc-shaped glasssubstrate. The process proceeds to step S2, and photoresist is formed onthe glass substrate. Then, the process proceeds to step S3, and thephotoresist formed on the glass substrate is cut (exposed) according toa data stream to be recorded in an optical disk. The process proceeds tostep S4, and the photoresist cut in step S3 is developed. The processproceeds to step S5, and an electric-conductivity process is applied tothe developed photoresist. Then, the process proceeds to step S6, andnickel electric casting is applied to the glass substrate on which thephotoresist to which electric-conductivity process has been applied isformed to form a (nickel) stamper. The process proceeds to step S7, andidentical optical-disks are formed by using the stamper made in step S6.

Improvement-information transfer achieved between user terminals 2through the management center 4 shown in FIG. 1 will be described nextby referring to FIG. 11.

In the following description, a user terminal which receives improvementinformation is called a user terminal 2 _(k), and a user terminal whichoffers the improvement information is called a user terminal 2 _(m).

The user terminal 2 _(k) which wants to obtain improvement informationrequests the improvement information from the management center 4through the network 3. When the management center 4 receives a requestfor the improvement information from the user terminal 2 _(k), themanagement center 4 searches for the user terminal 2 _(m) having therequired improvement information, and requests the improvementinformation from the user terminal 2 _(m) through the network 3. Theuser terminal 2 _(m) sends the improvement information to the managementcenter 4 through the network 3 in response to the request for theimprovement information sent from the management center 4. Themanagement center 4 receives the improvement information and sends it tothe user terminal 2 _(k) through the network 3.

In the embodiment shown in FIG. 11, the management center 4 relays theimprovement information sent from the user terminal 2 _(m), to the userterminal 2 _(k). It is also possible that the user terminal 2 _(m) sendsthe improvement information directly to the user terminal 2 _(k) throughthe network 3.

The improvement information can be sent as is. It can be sent after itis encrypted. As an encryption method, either a public-key encryptionmethod such as a Rivest-Shamir-Adleman (RSA) method or a private-keyencryption method such as a data-encryption-standard (DES) method can beused.

FIG. 12 shows an example structure of the user terminal 2 shown inFIG. 1. The example structure of the user terminal 2 applies when therecording medium 10 provided by the contents provider 1 is an opticaldisk.

An optical disk (hereinafter called an optical disk 10, if necessary)serving as the recording medium 10 is rotated at a predetermined speedby a spindle motor section 31. The spindle motor section 31 is driven bya rotation control signal sent from a CD processor section 34 so thatthe optical disk 10 has the predetermine rotation speed.

An optical pickup 32 emits laser light having a controlled amount oflight to the optical disk 10. This laser light is reflected from theoptical disk 10. Reflected light is incident on an optical detectionsection (not shown) of the optical pickup 32. The optical detectionsection of the optical pickup 32 is formed of a divided photodetector,generates a voltage signal corresponding to the reflected light byphotoelectric conversion and current-voltage conversion, and sends thesignal to a radio-frequency (RF) amplifier section 33.

The RF amplifier section 33 generates a read signal (so-called a sumsignal), a focus error signal, and a tracking error signal according tothe voltage signal sent from the optical pickup 32, and sends them tothe CD processor section 34.

The CD processor section 34 generates a focus control signal used forcontrolling an objective lens (not shown) of the optical pickup 32 suchthat the focal point of the laser light is located at a recording layerof the optical disk 10, according to the focus error signal sent fromthe RF amplifier section 33, and sends it to a driver 35. The CDprocessor section 34 also generates a tracking control signal used forcontrolling the objective lens of the optical pickup 32 such that thelaser light is emitted to the center position of a desired track,according to the tracking error signal sent from the RF amplifiersection 33, and sends it to the driver 35. The CD processor section 34further generates a sled control signal used for moving the opticalpickup 32 in the radial direction of the optical disk 10 such that aposition to which the laser light is emitted does not exceed a trackingcontrol area, and sends it to a sled motor section 36. The sled motorsection 36 moves the optical pickup 32 in the radial direction of theoptical disk 10 according to the sled control signal sent from the CDprocessor section 34.

The driver 35 generates a focus driving signal according to the focuscontrol signal sent from the CD processor section 34, and also generatesa tracking driving signal according to the tracking control signal sentalso from the CD processor section 34. The focus driving signal and thetracking driving signal are sent to an actuator (not shown) in theoptical pickup 32, and the position of the objective lens is controlledaccording to the signals. More specifically, with this control, thelaser light output from the optical pickup 32 is controlled so as tofocus on the center position of a desired track.

The CD processor section 34 applies asymmetry compensation andbinarization to the read signal sent from the RF amplifier section 33 toconvert it to a digital signal. Then, the CD processor section 34applies eight-to-fourteen modulation (EFM) to the digital signal, andperforms cross-interleave-Reed-Solomon-code (CIRC) error-correctingprocessing.

Musical-piece data serving as a content, obtained when the CD processorsection 34 performs the error-correcting processing is sent to acontents storage section 37 and stored (recorded). Contentsidentification information, improvement-information identificationinformation, and improvement information obtained when the CD processorsection 34 performs the error-correcting processing are sent to animprovement-information storage section 38 and stored (recorded).

The CD processor section 34 detects a signal used for framesynchronization from the read signal sent from the RF amplifier section33, generates a rotation control signal according to the read signalsuch that the optical disk 10 has a desired rotation speed, and sends itto the spindle motor section 31.

An improvement processing section 39 reads the musical-piece dataserving as a content, stored in the contents storage section 37 and theimprovement information stored in the improvement-information storagesection 38; and performs improvement processing for improving the soundquality of the musical-piece data read from the contents storage section37 by using the improvement information read from theimprovement-information storage section 38. The improvement processingsection 39 applies digital-to-analog (D/A) conversion to themusical-piece data having an improved sound quality, obtained by theimprovement processing, and outputs from a speaker (not shown).

As described above, there are a plurality of types ofimprovement-information pieces, and improvement processing for improvingthe sound quality of musical-piece data cannot be performed in somecases only with a certain type of improvement-information piece. In thecase in which bits obtained by dividing the low-order bits of theoriginal data of musical-piece data into a plurality of portions areused as improvement information as described by referring to FIG. 4,even if B14 and B15, for example, which are further lower-order bits,are obtained, when B6 to B13, which are higher-order bits than B14 andB15 are not obtained, the sound quality of the musical-piece data cannotbe improved. Therefore, the improvement information processing section39 performs improvement processing only when improvement informationrequired for improving sound quality is stored in theimprovement-information storage section 38, and outputs musical-piecedata stored in the contents storage section 37 without applyingimprovement processing when the required improvement information is notstored.

The types of improvement-information pieces can be recognized by theimprovement-information identification information stored in theimprovement-information storage section 38. The improvement processingsection 39 determines according to the improvement-informationidentification information whether improvement information required forimprovement processing is stored in the improvement-information storagesection 38.

A communication control section 40 performs communication controlthrough network 3. More specifically, the communication control section40 requests necessary improvement information from the management center4 through the network 3. In addition, the communication control section40 receives improvement information and others sent from the managementcenter 4 in response to the request, sends them to theimprovement-information storage section 38, and stores them in it.Furthermore, the communication control section 40 reads improvementinformation and others stored in the improvement-information storagesection 38 in response to a request sent from the management center 4,and sends them to the management center 4 through the network 3.

When the user terminal 2 obtains musical-piece data and others offeredthrough the network 3 by the contents provider 1, the communicationcontrol section 40 receives the data stream shown in FIG. 2. In the sameway as when the optical disk 10 is read, the musical-piece data is sentto the contents storage section 37 and stored, and contentsidentification information, improvement-information identificationinformation, and improvement information are sent to theimprovement-information storage section 38 and stored.

A control section 41 is connected to an operation section 42 and to adisplay section 43. The operation section 42 is operated to specify anoperation at the user terminal 2 or to switch the operation. In otherwords, when the operation section 42 is operated, the operation signalcorresponding to the operation is sent to the control section 41, thecontrol section 41 generates a control signal according to the operationsignal, and sends it to a necessary block. With this control, the userterminal 2 is controlled to perform the desired operation (process). Thedisplay section 43 receives a display signal from the control section 41to display the operation state of the user terminal 2 and othernecessary information.

To allow a user terminal 2 to receive improvement information fromanother user terminal 2 through the management center 4 and to offerimprovement information to another user terminal 2, it is necessary toperform user registration in the management center 4.

Registration request processing for requesting user registration fromthe management center 4 by a user terminal 2 will be described next byreferring to a flowchart shown in FIG. 13.

When the user operates the operation section 42 to perform theregistration request processing, the control section 41 makes thedisplay section 43 display a message requesting the optical disk 10 tobe loaded. When the user of the user terminal 2 loads the optical disk10 into the user terminal 2, the optical disk 10 is read in the userterminal 2. With this operation, musical-piece data is stored in thecontents storage section 37, and contents identification information,improvement-information identification information, and improvementinformation are stored in the improvement-information storage section38.

Then, the control section 41 controls the communication control section40 to establish a communication link with the management center 4through the network 3.

In step S11, the communication control section 40 reads the contentsidentification information and improvement-information identificationinformation stored in the improvement-information storage section 38,and includes them in a registration request message which requests userregistration. In addition, the communication control section 40 includesinformation (hereinafter called connection information, if necessary)required for the management center 4 to access the user terminal 2through the network 3, such as a telephone number and an InternetProtocol (IP) address, in the registration request message, and sendsthe message to the management center 4 through the network 3.

The management center 4 performs user registration processing, describedlater, in response to the registration request message sent from theuser terminal 2; includes user identification information used foridentifying the user terminal 2 in a registration completion messageindicating that user registration has been completed; and sends themessage. In step S12, the communication control section 40 determineswhether it has received the registration completion message from themanagement center 4.

When it is determined in step S12 that the registration completionmessage has not yet been received, the processing returns to step S12.When it is determined in step S12 that the registration completionmessage has been received, in other words, when the communicationcontrol section 40 has received the registration completion message sentfrom the management center 4, the processing proceeds to step S13, andthe communication control section 40 stores the user identificationinformation included in the registration completion message in a memory(not shown) built in the communication control section 40. Then, thecommunication control section 40 disconnects the communication link withthe management center 4 and finishes the registration requestprocessing.

Reproduction processing of musical-piece data, performed by a userterminal 2 will be described next in detail by referring to a flowchartshown in FIG. 14.

When the user loads the optical disk 10 into a user terminal 2 andoperates the operation section 42 to read data from the optical disk 10,for example, the control section 41 controls a necessary block toreproduce from the optical disk 10 musical-piece data, contentsidentification information, improvement-information identificationinformation, and improvement information stored in the optical disk 10,in step S21. As described above, the musical-piece data is stored in thecontents storage section 37, and the contents identificationinformation, the improvement-information identification information, andthe improvement information are stored in the improvement-informationstorage section 38.

Then, the processing proceeds to step S22, and the improvementprocessing section 39 refers to the improvement-informationidentification information stored in the improvement-information storagesection 38 to determine whether a type of improvement information ismissing in order to improve the sound quality of the musical-piece datastored in the contents storage section 37. When the improvementprocessing section 39 determines that no type of improvement informationis missing, in other words, when all types of improvement informationrequired for improving the sound quality of the musical-piece datastored in the contents storage section 37 have already been obtained byimprovement-information acquisition processing, described below, andstored in the improvement-information storage section 38, steps from S23to S25 are skipped and the processing proceeds to step S26.

In step S26, the improvement processing section 39 uses all the types ofimprovement information stored in the improvement-information storagesection 38 to improve the sound quality of the musical-piece data storedin the contents storage section 37. The processing proceeds to step S27,and the musical-piece data of which the sound quality has been improvedis output. The reproduction processing is finished.

Therefore, in this case, the musical-piece data of which the soundquality has been improved as much as possible is output.

When it is determined in step S22 that a type of improvement informationis missing, the processing proceeds to step S23, and the control section41 determines whether it requests the type of improvement informationmissing from the management center 4 (from another user terminal 2through the management center 4).

More specifically, the control section 41 makes the display section 43display an inquiry message indicating whether to request the improvementinformation, and determines whether to request the improvementinformation according to a user response to the inquiry message.

When the improvement information is requested from the management center4 and the user terminal 2 obtains the improvement information, themanagement center 4 collects money as the consideration of theimprovement information, as described later. Depending on the user, theacquisition of the improvement information is not desired. Therefore, itis determined in step S23 whether the improvement information isrequired or not.

When it is determined in step S23 that the improvement information isrequired, in other words, when the user operates the operation section42 to request the improvement information in response to the inquirymessage, the processing proceeds to step S24. Improvement-informationacquisition processing, described later, is performed and the processingproceeds to step S25.

In step S25, the improvement-information processing section 39 refers tothe improvement-information storage section 38 to determine whether alltypes of improvement-information pieces are collected by theimprovement-information acquisition processing performed in step S24.When it is determined that all types of improvement-information pieceshave been collected, in other words, when all types ofimprovement-information pieces required for improving the sound qualityof the musical-piece data stored in the contents storage section 37 arestored in the improvement-information storage section 38, the processingproceeds to step S26.

Also in this case, as described before, in step S26, the improvementprocessing section 39 uses all the types of improvement informationstored in the improvement-information storage section 38 to improve thesound quality of the musical-piece data stored in the contents storagesection 37. The processing proceeds to step S27, and the musical-piecedata of which the sound quality has been improved is output. Thereproduction processing is finished.

Therefore, also in this case, the musical-piece data of which the soundquality has been improved as much as possible is output.

When the user operates the operation section 42 in response to theinquiry message so as not to request the improvement information and itis determined in step S23 that the improvement information is notrequired, or when it is determined in step S25 that all types ofimprovement-information pieces have not yet collected even if theimprovement-information acquisition processing was performed in stepS24, the processing proceeds to step S28. The improvement processingsection 39 determines whether it is possible to perform improvementprocessing for improving the sound quality of the musical-piece data byusing only improvement information currently stored in theimprovement-information storage section 38.

When it is determined in step S28 that it is impossible to performimprovement processing by using only the improvement informationcurrently stored in the improvement-information storage section 38, stepS26 is skipped and the processing proceeds to step S27. Theimprovement-processing section 39 reads the musical-piece data stored inthe contents storage section 37, and outputs it as is without applyingthe improvement processing. The reproduction processing is finished.

Therefore, in this case, the musical-piece data having a low soundquality or a normal sound quality is output.

When it is determined in step S28 that it is possible to perform theimprovement processing by using only the improvement informationcurrently stored in the improvement-information storage section 38, theprocessing proceeds to step S26. The improvement processing section 39uses the improvement information stored in the improvement-informationstorage section 38 to improve the sound quality of the musical-piecedata stored in the contents storage section 37. The processing proceedsto step S27, and the improvement processing section 39 outputs themusical-piece data of which the sound quality has been improved. Thereproduction processing is finished.

Therefore, in this case, the musical-piece data of which the soundquality has been improved within the range corresponding to theimprovement information stored in the improvement-information storagesection 38 is output.

The improvement-information acquisition processing to be performed instep S24 in FIG. 14 will be described next by referring to a flowchartshown in FIG. 15.

The communication control section 40 first establishes a communicationlink with the management center 4 through the network 3. Then, in stepS31, the communication control section 40 reads the contentsidentification information and improvement-information identificationinformation, and includes them in an improvement-information requestmessage for requesting improvement information. In addition, thecommunication control section 40 reads the user identificationinformation stored in the memory built in the communication controlsection 40, includes the user identification information in theimprovement-information request message, and sends the message to themanagement center 4 through the network 3.

When the management center 4 receives the improvement-informationrequest message, it determines whether it is possible to provide theimprovement information requested by the improvement-information requestmessage, as described later. When it is possible, the management center4 sends the improvement information to the user terminal 2 through thenetwork 3, and when it is not possible, the management center 4 sends anproviding-impossible message indicating that the improvement informationcannot be offered, to the user terminal 2 through the network 3. Thecommunication control section 40 determines in step S32 whether it hasreceived the providing-impossible message from the management center 4.

When it is determined in step S32 that the communication control section40 has received the providing-impossible message, in other words, whenthe communication control section 40 has received theproviding-impossible message from the management center 4, themanagement center 4 disconnects the communication link with themanagement center 4, steps from S33 to S35 are skipped, and theimprovement-information acquisition processing is finished (returning tothe main program is performed).

When it is determined in step S32 that the communication control section40 has not received the providing-impossible message, in other words,when the management center 4 has sent the improvement informationrequested by the improvement-information request message and othernecessary information (such as improvement-information identificationinformation used for identifying the improvement information andcontents identification information used for identifying themusical-piece data of which the sound quality is to be improved by theimprovement information), the processing proceeds to step S33, thecommunication control section 40 receives the improvement informationand others from the management center 4, and it determines whetherreceiving has been performed successfully.

Whether the user terminal 2 has successfully received the informationfrom the management center 4 can be determined, for example, bycomparing the size sent from the management center 4 before themanagement center 4 sends the information, of the information to be sentfrom the management center 4, with the size of the information actuallyreceived from the management center 4.

When it is determined in step S33 that the improvement information andothers have not successfully been received from the management center 4,the processing proceeds to step S34, and the communication controlsection 40 requests re-transmission of the improvement information andothers from the management center 4. The processing returns to step S33and subsequent processes are performed again.

When it is determined in step S33 that the improvement information andothers have successfully been received from the management center 4, theprocessing proceeds to step S35, and the communication control section40 sends the improvement information and others successfully received tothe improvement-information storage section 38 and stores them in it.The processing proceeds to step S36. In step S36, the communicationcontrol section 40 sends a successful-receiving message indicating thatthe information has been successfully received to the management center4. Then, the management center 4 disconnects the communication link. Theimprovement-information acquisition processing is finished.

The improvement-information acquisition processing, described above, isperformed in the reproduction processing shown in FIG. 14. In addition,the improvement-information acquisition processing can also be performedaccording to a user request.

When the improvement information is requested from the management center4 by the improvement-information request message sent from the userterminal 2, the management center 4 obtains the improvement informationfrom another user terminal 2 and sends it to the user terminal 2 whichhas requested it. This means that the another user terminal 2 providesthe management center 4 with the improvement information.

Improvement-information providing processing in which a user terminal 2provides the management center 4 with improvement information will bedescribed next by referring to a flowchart shown in FIG. 16.

When the communication control section 40 receives a request forimprovement information, sent from the management center 4 as describedlater, the user terminal 2 reads data from the optical disk 10 asdescribed above in step S41, and stores musical-piece data in thecontents storage section 37 and contents identification information,improvement-information identification information, and improvementinformation in the improvement-information storage section 38.

The processing proceeds to step S42. The communication control section40 reads the contents identification information, theimprovement-information identification information, and the improvementinformation stored in the improvement-information storage section 38,and sends them to the management center 4 together with useridentification information stored in the memory built in thecommunication control section 40. The processing proceeds to step S43.

In step S43, the communication control section 40 determines whether ithas received a re-transmission request from the management center 4.When the communication control section 40 determines that it hasreceived the request, the processing returns to step S42, and subsequentprocesses are performed again.

When the communication control section 40 determines in step S43 that ithas not received the request, the improvement-information providingprocessing is finished.

FIG. 17 shows an example structure of the management center 4 shown inFIG. 1.

A communication control section 51 performs communication controlthrough the network 3 to receive necessary data from a registrationsection 52, an acquisition section 54, or a providing section 56 andsend it to the network 3, and to receive data from the network 3 andsend it to the registration section 52, the acquisition section 54, orthe providing section 56.

The registration section 52 stores information required for userregistration in a user data base 53 and an accounting data base 59according to data sent from the communication control section 51. Theregistration section 52 also issues user identification information atuser registration and sends it to the communication control section 51.

The user data base 53 relates necessary information to the useridentification information issued to the user terminal 2 and storesthem.

The acquisition section 54 performs control in order to obtainimprovement information from the user terminal 2 according to data sentfrom the communication control section 51. In other words, theacquisition section 54 controls a search section 57 to detect the userwho owns an optical disk 10 in which the necessary improvementinformation has been stored. The acquisition section 54 also controlsthe communication control section 51 to obtain the improvementinformation and others from the user terminal 2 of the user and to sendthem to a memory 55 and store in it. The acquisition section 54 alsosends user identification information for identifying the user terminal2 which has obtained the improvement information and others to anaccounting processing section 58.

The memory 55 temporarily stores the improvement information and otherssent from the acquisition section 54.

The providing section 56 reads the improvement information and othersstored in the memory 55, and controls the communication control section51 to send the improvement information and others to the user terminal2. The providing section 56 also sends user identification informationfor identifying the user terminal 2 which has provided the improvementinformation to the accounting processing section 58.

The search section 57 searches the user data base 53 for information(user information) related to the user who owns the necessaryinformation under the control of the acquisition section 54, and sendsthe information to the acquisition section 54.

The accounting processing section 58 performs accounting processing forthe user of the user terminal 2 determined from user identificationinformation sent from the acquisition section 54 or the providingsection 56 by referring to the accounting data base 59. The accountingdata base 59 stores accounting information required for the accountingprocessing performed by the accounting processing section 58.

When the management center 4 structured as described above receives aregistration request message from a user terminal 2, as described aboveby referring to FIG. 13, the management center 4 performs userregistration processing according to a flowchart shown in FIG. 18.

A registration request message sent from the user terminal 2 is receivedby the communication control section 51 and sent to the registrationsection 52. When the registration section 52 receives the registrationrequest message, the registration section 52 issues a unique useridentification information in step S51. The processing proceeds to stepS52. In step S52, the registration section 52 relates the contentsidentification information, the improvement-information identificationinformation, and the connection information included in the registrationrequest message sent from the communication control section 51, to theuser identification information issued in step S51 to generate userinformation, sends the user information to the user data base 53, andregisters the user information in the user data base 53.

The processing proceeds to step S53. The registration section 52 makesan entry for storing the user accounting information corresponding tothe user identification information issued in step S51, in theaccounting data base 59. The processing proceeds to step S54.

In step S54, the registration section 52 includes the useridentification information issued in step S51 in a registrationcompletion message indicating that user registration has been completed,sends the message to the communication control section 51, and makes thecommunication control section 51 send the registration completionmessage to the user terminal 2 which sent the registration requestmessage. The user registration processing is finished.

As described above, when the user terminal 2 _(k) which has finisheduser registration sends a request for improvement information, themanagement center 4 obtains the improvement information from anotheruser terminal 2 _(m) which has finished user registration, and performsprocessing (hereinafter called improvement-information relay processing)for providing the user terminal 2 _(k) with the improvement information.The improvement-information relay processing will be described below byreferring to a flowchart shown in FIG. 19.

As described above by referring to FIG. 15, when the user terminal 2_(k) sends an improvement-information request message to the managementcenter 4, the improvement-information request message is received by thecommunication control section 51, and the improvement-information relayprocessing is started.

The communication control section 51 sends the receivedimprovement-information request message to the acquisition section 54.The acquisition section 54 recognizes requested improvement informationaccording to the improvement-information request message in step S61.

The improvement-information request message includes contentsidentification information and improvement-information identificationinformation, as described above. The musical-piece data of which thesound quality is to be improved by the user terminal 2 _(k) which sentthe improvement-information request message can be identified accordingto the contents identification information. A type of improvementinformation already obtained by the user terminal 2 _(k) which sent theimprovement-information request message can be identified according tothe improvement-information identification information. Therefore,according to the contents identification information and theimprovement-information identification information included in theimprovement-information request message, improvement informationrequested by the user terminal 2 _(k) which sent theimprovement-information request message, that is, improvementinformation required for improving the sound quality of themusical-piece data of which the sound quality is to be improved by theuser terminal 2 _(k) but not yet obtained by the user terminal 2 _(k)(not yet stored in the improvement-information storage section 38 (FIG.12)) can be recognized.

When the acquisition section 54 recognizes the improvement informationrequested by the user terminal 2 _(k), in step S61, the processingproceeds to step S62 and the acquisition section 54 controls the searchsection 57 so as to search for a user terminal 2 which owns theimprovement information.

The search section 57 searches for a user terminal 2 which owns theimprovement information requested by the user terminal 2 _(k) byreferring to the user data base 53. More specifically, the searchsection 57 refers to contents identification information andimprovement-information identification information stored in the userdata base 53 to search for a user terminal 2 which owns the improvementinformation requested by the user terminal 2 _(k), and sends the resultof searching to the acquisition section 54.

The acquisition section 54 determines from the result of searching sentfrom the search section 57 whether there is a user terminal 2 which ownsthe improvement information requested by the user terminal 2 _(k). Whenit is determined that there is not such a user terminal 2, in otherwords, when the search section 57 cannot obtain the user identificationinformation of a user terminal 2 which owns the improvement informationrequested by the user terminal 2 _(k), the processing proceeds to stepS64 and the acquisition section 54 controls the communication controlsection 51 to send a providing-impossible message indicating that theimprovement information cannot be requested, to the user terminal 2 _(k)which has requested the improvement information. Theimprovement-information relay processing is terminated.

When it is determined in step S63 that there exists such a terminal 2which owns the improvement information requested by the user terminal 2_(k), in other words, when the search section 57 has obtained the useridentification information of a user terminal 2 which owns theimprovement information requested by the user terminal 2 _(k), theprocessing proceeds to step S65 and the acquisition section 54 controlsthe communication control section 51 to request the improvementinformation requested by the user terminal 2 _(k), from the userterminal 2 _(m) identified by the user identification informationobtained by the search section 57.

In this case, the communication control section 51 establishes acommunication link with the user terminal 2 _(m) identified by the useridentification information, according to the connection informationrelated to the user identification information obtained by the searchsection 57, and requests the improvement information requested by theuser terminal 2 _(k).

There is a case in which the user terminal 2 _(k) requests a pluralityof types of improvement-information pieces, and different user terminals2 own the plurality of types of improvement-information pieces. In thiscase, the processes of step S65 to step S68, described later, areexecuted for each of the different terminals 2.

There is also a case in which a plurality of user terminals 2 own a typeof improvement information requested by the user terminal 2 _(k). Inthis case, the type of improvement information can be requested from oneof the plurality of user terminals 2. One of the plurality of userterminals 2 is selected by randomly selecting one user terminal 2 or byselecting, for example, a user terminal 2 which needs the minimumcommunication charge. It is also possible to select a user terminal 2which provides the highest communication quality.

When a plurality of user terminals 2 own a type of improvementinformation requested, instead of selecting one among the plurality ofuser terminals 2 as described above, two or more (even all) userterminals can be selected. When two or more user terminals 2 areselected, it is possible that an identical type of improvementinformation is obtained from each of the two or more user terminals.When two or more user terminals 2 are selected, it is also possible thatall of identical types of improvement information are obtained from eachof the two or more user terminals 2. In this case, robustness ofimprovement information is improved. In other words, even ifcommunication quality is poor, since all of identical types ofimprovement information are obtained from each of the two or more userterminals 2, if an error occurs during transmission or receiving ofimprovement information, the error is corrected and correct improvementinformation is obtained.

In the present embodiment, to make a description simple, when aplurality of user terminals 2 own a type of improvement informationrequested, it is assumed as described above that one user terminal 2_(m) is selected among the plurality of user terminals 2, andimprovement information is requested from the one user terminal 2 _(m)in step S65.

When a request for improvement information is sent to the user terminal2 _(m) in step S65 and the user terminal 2 _(m) receives the request forimprovement information, the user terminal 2 _(m) performs theimprovement-information providing processing, described by referring toFIG. 16, to send the improvement information requested in step S65 tothe management center 4 together with its improvement-informationidentification information, contents identification information, anduser identification information. The communication control section 51receives the improvement information and others sent in that way.

The processing proceeds to step S66, and the communication controlsection 51 determines whether it has successfully received theimprovement information and others sent from the user terminal 2 _(m).When it is determined in step S66 that the improvement information andothers sent from the user terminal 2 _(m) have not been successfullyreceived, the processing proceeds to step S67 and the communicationcontrol section 51 sends a re-transmission request to the user terminal2 _(m). Then, the processing returns to step S65.

When it is determined in step S66 that the improvement information andothers sent from the user terminal 2 _(m) have been successfullyreceived, the communication control section 51 sends the improvementinformation and others successfully received to the acquisition section54. When the acquisition section 54 receives the improvement informationand others from the communication control section 51, it sends them tothe memory 55 and stores them in the memory 55. The processing proceedsto step S68, and the acquisition section 54 sends the useridentification information of the user terminal 2 _(m), sent togetherwith the improvement information to the accounting processing section 58to make the accounting processing section 58 execute accountingprocessing and update the accounting information of the accounting database 59.

More specifically, the accounting processing section 58 reads theaccounting information specified by the user identification informationsent from the acquisition section 54, from the accounting data base 59,and calculates a charge for the improvement information obtained fromthe user terminal 2 _(m). In addition, the accounting processing section58 adds the calculated charge to the accounting information read fromthe accounting data base 59, and writes the new accounting informationobtained by this addition to the accounting data base 59 in anoverwriting manner.

Then, the processing proceeds to step S69, and the providing section 56reads the improvement information from the memory 55 together with itsimprovement-information identification information and the contentsidentification information, and controls the communication controlsection 51 to send the improvement information to the user terminal 2_(k). Then, the processing proceeds to step S70.

Since the user terminal 2 _(k) sends a re-transmission request or asuccessful-receiving message, as described in theimprovement-information acquisition processing by referring to FIG. 15,the communication control section 51 determines in step S70 whether theuser terminal 2 _(k) has sent a re-transmission request or asuccessful-receiving message. When it is determined in step S70 that are-transmission request has been sent, the processing returns to stepS69, and the improvement information and others stored in the memory 55are re-transmitted.

When it is determined in step S70 that a successful-receiving messagehas been sent, the processing proceeds to step S71, and the providingsection 56 recognizes the user identification information of the userterminal 2 _(k) to which the improvement information was sent(provided), from the improvement-information request message received bythe communication control section 51, and sends it to the accountingprocessing section 58. The accounting processing section 58 executes theaccounting processing, and updates the accounting information of theaccounting data base 59. The improvement-information relay processing isterminated.

More specifically, the accounting processing section 58 reads theaccounting information specified by the user identification informationsent from the providing section 56, from the accounting data base 59,and calculates a charge to be collected for the improvement informationsent to the user terminal 2 _(k). In addition, the accounting processingsection 58 adds the calculated charge to the accounting information readfrom the accounting data base 59, and writes the new accountinginformation obtained by this addition to the accounting data base 59 inan overwriting manner.

Then, the accounting processing section 58, for example, transfers themoney for providing the improvement information to the bank account ofthe user who provided it, or charges the money for purchasing theimprovement information directly to the bank account of the user whopurchased it.

The accounting processing can be performed by the accounting processingsection 58, for example, in the following way.

When low-order bits of the original data of musical-piece data aredivided into a plurality of bits and used as improvement information asdescribed by referring to FIG. 4, it is expected that among thelow-order bits serving as the improvement information, the lower a bitis, the lower the probability (the need) of providing the bit for otheruser terminals 2 is, and the higher a bit is, the higher the probability(the need) of providing the bit for other user terminals 2 is. It ispossible that a charge for lower bits among the low-order bits servingas the improvement information is set low and a charge for higher bitsamong the low-order bits serving as the improvement information is sethigh. It is also possible that a purchase charge for an optical disk 10in which lower bits are recorded among the low-order bits serving as theimprovement information is set low and a purchase charge for an opticaldisk 10 in which higher bits are recorded among the low-order bitsserving as the improvement information is set high. In this case, evenif the optical disk 10 is expensive, since the optical disk 10 storesimprovement information which is to be requested by another userterminal 2 at a high possibility, the user who purchased it can providethe improvement information to reimburse a part or the whole of themoney paid for the expensive optical disk 10 as an information providingfee.

It is also possible that the management center 4 does not executeaccounting processing, that is, the information providing fee ofimprovement information and the purchase charge thereof are set free;and unlike the case described above, a purchase charge for an opticaldisk 10 in which lower bits are recorded among the low-order bitsserving as the improvement information is set high and a purchase chargefor an optical disk 10 in which higher bits are recorded among thelow-order bits serving as the improvement information is set low. Inthis case, the purchase charge for the optical disk 10 which storesimprovement information to be requested by other user terminals 2 at ahigh possibility is low, but it is necessary to frequently provide otheruser terminals 2 with the recorded improvement information. The purchasecharge for the optical disk 10 which stores improvement information tobe requested by other user terminals 2 at a low possibility is high, butit is not necessary to frequently provide other user terminals 2 withthe recorded improvement information.

In a case in which the management center 4 executes the accountingprocessing, when an identical type of improvement information isobtained from a plurality of user terminals 2, as described above, it ispossible that the money to be paid to one user terminal 2 if theimprovement information is obtained from the user terminal 2 is equallydivided for the plurality of user terminals 2 and paid.

As described above, in the management center 4, user information whichincludes user identification information identifying the user terminals2 and improvement-information identifying information identifyingimprovement information recorded into the optical disks 10 processed bythe user terminals 2 are registered into the user data base 53; when auser terminal 2 _(k) requests improvement information, another userterminal 2 _(m) which can provide necessary improvement information issearched for according to the user information; and the necessaryimprovement information is obtained from the user terminal 2 _(m)searched for and provided for the user terminal 2 _(k). Therefore, theusers are allowed to buy and sell improvement information for improvingthe quality of purchased data to and from each other. As a result, a newmarket is developed and a new business is made.

The series of above-described processing can be executed not only byhardware but also by software. When the series of processing is executedby software, a program constituting the software is installed into ageneral-purpose computer or the like.

FIG. 20 shows an example structure of a computer into which a programwhich executes the series of above-described processing is installed,according to an embodiment.

The program can be recorded in advance into a hard disk 105 or aread-only memory (ROM) 103 serving as a recording medium which is builtin the computer.

Alternatively, the program can be stored (recorded) temporarily orperpetually into a removable recording medium 111, such as a floppydisk, a compact disc read-only memory (CD-ROM), a magneto-optical (MO)disk, a digital versatile disk (DVD), a magnetic disk, or asemiconductor memory. Such a removable recording medium 111 can beoffered as so-called package software.

The program can be installed into the computer from the removablerecording medium 111, described above. Alternatively, the program can betransferred by radio from a downloading site to the computer through anartificial satellite for digital satellite broadcasting, or to thecomputer by wire through a network such as a local area network (LAN) orthe Internet; received by a communication section 108 and installed intothe built-in hard disk 105.

The computer includes a central processing unit (CPU) 102. The CPU 102is connected to an input and output interface 110 through a bus 101.When the user operates an input section 107 formed of a keyboard, amouse and a microphone to input a command through the input and outputinterface 105, the CPU 102 executes the program stored in the ROM 103according to the command. Alternatively, the CPU 102 loads into a randomaccess memory (RAM) 104 the program stored in the hard disk 105; theprogram transferred through the satellite or the network, received bythe communication section 108, and installed into the hard disk 105; orthe program read from the removable recording medium 111 loaded into adrive 109, and installed into the hard disk 105; and executes it. TheCPU 102 executes the processing according to the above-describedflowchart, or executes processing performed by the structure shown inthe above-described block diagram. The CPU 102 outputs the processingresult, for example, through the input and output interface 110 to anoutput section 106 formed of a liquid-crystal display (LCD) and aspeaker; sends the processing result from the communication section 108;or stores the processing result in the hard disk 105, as required.

In the present specification, the steps describing the program forexecuting various types of processing are not necessarily processed in atime sequential manner in the order in which the steps are described inthe flowcharts. Processing to be executed in parallel or individually,such as parallel processing or processing by objects, is also included.

The program may be executed by one computer. It may bedistribution-processed by a plurality of computers. It may also betransferred to a remote computer and executed.

1. An information processing apparatus comprising: a reading unitconfigured to read from a recording medium degraded data and firstimprovement information used for improving the quality of the degradeddata; an improvement-information requesting unit configured to request asecond improvement information used for improving the quality of thedegraded data; and a quality improving unit configured to improve thequality of the degraded data according to at least both the firstimprovement information and the second improvement information andproduce high quality data, wherein an information amount of the highquality data is greater than an information amount of the degraded datawherein the first improvement information and the second improvementinformation are data bits added to data bits of the degraded data, andwherein the degraded data are data having fewer data bits of originaldata. 2-3. (canceled)
 4. An information processing method comprising:reading from a recording medium degraded data and first improvementinformation used for improving the quality of the degraded data;requesting a second improvement information used for improving thequality of the degraded data; and improving the quality of the degradeddata according to at least both the first improvement information andthe second improvement information and producing high quality data,wherein an information amount of the high quality data is greater thanan information amount of the degraded data wherein the first improvementinformation and the second improvement information are data bits addedto data bits of the degraded data, and wherein the degraded data aredata having fewer data bits of original data. 5-6. (canceled)
 7. Acomputer-readable medium storing a computer program for performing aninformation processing method, the method comprising: reading from arecording medium degraded data and first improvement information usedfor improving the quality of the degraded data; requesting a secondimprovement information used for improving the quality of the degradeddata; and improving the quality of the degraded data according to atleast both the first improvement information and the second improvementinformation and producing high quality data, wherein an informationamount of the high quality data is greater than an information amount ofthe degraded data wherein the first improvement information and thesecond improvement information are data bits added to data bits of thedegraded data, and wherein the degraded data are data having fewer databits of original data. 8-9. (canceled)